Climate and southern Africa's water-energy-food nexus

In southern Africa, the connections between climate and the water-energy-food nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and Gross Domestic Product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose; the Southern African Development Community, the Southern African Power Pool, and trade of agricultural products amounting to significant transfers of embedded water

Nonadiabatic laser-induced alignment of iodobenzene molecules

Nonadiabatic alignment of an asymmetric top molecule induced by a short, moderately intense laser pulse is studied theoretically and experimentally. Numerically, we solve nonperturbatively the time-dependent Schrödinger equation for a general asymmetric top molecule subject to a moderately intense laser field, and analyze the dependence of the alignment dynamics on the field strength and on the rotational temperature. Experimentally, we use time-resolved photofragment imaging to measure the time-dependent angular distributions of the spatial orientation of the molecules. Our studies, using iodobenzene as a test molecule, focus on the short-time alignment dynamics, during and after the pulse

Satisfaction with care in HIV-infected patients treated with long term follow up antiretroviral therapy: the role of social vulnerability

International audienceThe aim of this study was to determine factors associated with complete satisfaction with the care provided (satisfaction with physicians and satisfaction with services and organization) among HIV-infected patients followed-up in the French ANRS CO8 APROCO-COPILOTE cohort. Analyses focused on cross-sectional data collected during the ninth year of cohort follow-up. Satisfaction with care (Bredard & al, 2005), sociodemographic characteristics and behavioral data were collected using self-administered questionnaires, while clinical data were derived from medical records. Complete satisfaction with care was defined as being 100% satisfied. Two logistic regression models were used to identify predictors of (i) complete satisfaction with physicians (n=404) and (ii) complete satisfaction with services and organization (n=396). Sixteen percent of patients were completely satisfied with physicians while 15.9% were completely satisfied with services and organization. Being older and reporting fewer discomforting antiretroviral therapy (ART) side effects were factors independently associated with complete satisfaction with both physicians and services and organization. Strong support from friends and absence of hepatitis C (HCV) co-infection were independently associated with complete satisfaction with physicians, while strong support from one's family and comfortable housing conditions were independently associated with complete satisfaction with services and organization. Even after nine years of follow-up, social vulnerabilities still strongly influence HIV-infected patients' interactions with the health care system. Day-to-day experience with the disease, including perceived treatment side effects, appears to play a key role in the quality of these interactions. More attention should be given to patient satisfaction, especially for socially vulnerable patients, in order to avoid potentially detrimental consequences such as poor adherence to ART

Sub-terahertz phonon dynamics in acoustic nanocavities

International audienceWe report a direct determination of the dynamic behavior of confined acoustic phonons in nanocavities by picosecond acoustics. We provide the broadband, high resolution transmission amplitude curve in the sub-terahertz range and we give evidence of resonant transmission peaks in three successive stop bands, in quantitative agreement with transfer matrix simulations. We demonstrate transit times in the nanosecond range at the cavity peaks reflecting the strong phonon confinement within the cavity layer and picosecond times in the stop bands, shorter than in any of the constituting materials, a tunneling effect known in photonic systems as superluminal propagation